The subject matter disclosed herein relates to magnetic resonance imaging (MRI), and more specifically, to systems and methods for producing T2 contrast preparatory pulses that are robust to magnetic field inhomogeneity and other imperfections like flow or motion, and optimize image contrast.
Generally, an MRI image of a subject (e.g., a patient) is produced by measuring properties of the gyromagnetic materials of the subject, such as hydrogen nuclei. These properties are usually obtained by measurement of emissions of the gyromagnetic materials as a response to an excitation from an application of magnetic fields. These magnetic fields generally include a strong primary magnetic field, magnetic field gradients, and radiofrequency (RF) magnetic field excitation pulses.
An MRI system may be used to produce different types of contrast based on a combination of properties of the gyromagnetic materials and the manner in which the magnetic fields are applied. For example, an MRI system may produce proton density images, T1-weighted images, T2-weighted images, etc., based on its suitability for the application. In some medical contexts, for example, T1-weighted images may be suitable to highlight fat tissue, while T2-weighted images may be suitable to highlight water content.
A contrast manipulation pulse sequence prior to data acquisition may improve the quality of the obtained image. One of these contrast manipulation pulses can be a T2 preparation pulse. Usually, T2 preparatory pulses are composed by a series of non-selective block pulses, which are susceptible to magnetic field inhomogeneity, and may lead to undesired artifacts in the image.